#include <stdio.h>
#include <time.h>

time_t start, end;

int main()
{
	int i;
	start = time(NULL);
	printf("start=%ld\n",start);
	for(i=0;i<2019132600;i++);
	end = time(NULL);
	printf("end = %ld\n");
	printf("time of for is %ld\n",end-start);
	return 0;

}
